This invention relates to a liquid supply system and in particular to a continuous supply system utilizing stacked tanks.
It is not uncommon for an in-plant liquid supply system to consist of a fifty-five gallon drum connected to a pumping or receiving system for drawing liquids from the drum for use as needed in the plant. When the drum is emptied, the pumping or receiving system is disconnected from the drum, the emptied drum moved away and a full drum moved into place and connected to the pumping or receiving system for a continuation of the liquid supply.
Such a system, however, has several disadvantages associated with it. A fifty-five gallon drum typically includes an opening in its top through which a pick-up tube must be inserted to the bottom of the drum for pumping liquids from the drum. During a change from one drum to the next, there is a possibility of leakage from the pick-up tube. In addition, handling of drums often requires manual handling which provides an opportunity for injury to the plant personnel and also for spillage from the drum. During use or changeover of drums, such a system may allow fumes to escape from the drum and may provide a hazard for the plant personnel. Once emptied, a drum must be properly disposed of by the liquid user which may prove to be difficult in the case of hazardous liquids. Another disadvantage with such a system is that during a changeover between drums, the liquid supply is temporarily interrupted.
Accordingly, it is an object of the present invention to provide a continuous liquid supply system without the disadvantages described above.
The liquid supply system of this invention includes a stationary in-plant supply tank which is located at the point of liquid usage. The supply tank is filled in the plant from portable transport tanks which are used for transporting the liquid from the liquid supplier to the user. The in-plant supply tank is positioned at the point of use and connected to the liquid pumping or receiving system through a discharge outlet at the lower end of the supply tank. The transport tank is placed on top of the supply tank and is connected to the supply tank through a lower discharge outlet in the transport tank which is connected to an upper inlet in the supply tank by a transport hose assembly. When the liquid level in the supply tank reaches a predetermined lowered level, the transport tank is emptied into the supply tank. The transport tank is then disconnected from the supply tank, removed from on top of the supply tank, and returned to the supplier for recycling.
The liquid supply system of this invention is advantageous in that it is a closed system, minimizing the possibility of leakage which can occur in the handling of fifty-five gallon drums. The closed system further minimizes the possibility of fumes being released into the plant atmosphere. By employing sloped bottom tanks for the transport tank, waste resulting from the inability to completely empty the tank is virtually eliminated. The tank can be returned to the supplier for recycling so any residual liquid remaining in the tank does not present a disposal concern for the user.
A further advantage of this supply system is that the liquid supply is never interrupted because the supply tank is never completely emptied or disconnected from the pumping or receiving system.
Further objects, features and advantages of the invention will become apparent from a consideration of the following description and the appended claims when taken in connection with the accompanying drawings.